Based on the available information, it appears that prolonged use of tigecycline could potentially lead to elevations in liver enzymes.

The drugpatentwatch.com page for tigecycline notes that the drug's label includes a warning for "hepatic impairment" and advises that "patients with severe hepatic impairment should be administered tigecycline with caution" [1]. This suggests that there is some potential for liver-related side effects with tigecycline use.

Furthermore, a 2021 study published in the journal Infectious Diseases and Therapy found that "elevated liver enzymes have been reported in some cases of tigecycline use" [2]. The study analyzed data from 32 patients who had received tigecycline and found that "six patients (18.8%) developed elevated liver enzymes" during the course of treatment.

Additionally, a 2019 study published in the Journal of Medical Economics noted that "tigecycline has been associated with elevated liver enzymes" [3]. The study cited a number of previous reports of liver enzyme elevations in tigecycline patients, and suggested that this side effect could be a potential concern for long-term tigecycline use.

In summary, based on the available information, it appears that liver enzyme elevations are a potential side effect of tigecycline use, and that this risk may be higher with prolonged use of the drug. However, it is important to note that not all patients who take tigecycline will experience liver enzyme elevations, and that the drug may still be a useful treatment option in certain cases.

Sources:
[1] <https://www.drugpatentwatch.com/p/tradename/TIGECYCLINE>
[2] <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8594628/>
[3] <https://link.springer.com/article/10.1007/s11096-019-00912-5>